Liquefied gas tanks are known for example from document FR3008765. That document describes a methane tanker tank comprising a plurality of longitudinal tank walls and a plurality of transverse tank walls. Each wall of the tank comprises a double sealing membrane intercalated with a double insulating barrier.
When the liquefied gas is being loaded and offloaded, the change in temperature imposes high thermal deformations and therefore stresses on the sealed membranes of the tank. Likewise, during transport at sea, the movement of the liquefied gas in the tank applies strong forces to the insulating barriers and the membranes of the tank. In order to avoid impairment of the sealing of the tank, according to document FR3008765, the sealed membranes of the tank are anchored on the bearing structure using anchoring couplers in the zone where the longitudinal walls meet the transverse walls. The sealed membranes are connected to the coupler by composite beams fixed to an internal face of insulating box structures that form the thermally insulating barriers.
Document WO2017064413 describes a sealed and thermally insulating structure in particular for liquefied petroleum gas (LPG). In document WO2017064413, anchor strips are fixed to insulating edging blocks during prefabrication. The insulating edging blocks and the anchor strips mounted together are then aligned along the edge corner during fabrication of the tank in the bearing structure. The angle pieces of the membrane are welded on the anchor strips in a subsequent step.